Fusing Keys for Secret Communications: Towards Information-Theoretic Security

TL;DR

This paper introduces a key-fusing framework that enhances the resilience of secret communications against key exposure by combining multiple imperfect keys, potentially enabling information-theoretic security.

Contribution

It proposes a novel key-fusing scheme that improves security against key exposure and integrates diverse key sources for robust secret communication.

Findings

Significantly reduces secret outage probability.

Enables practical use of high-exposure key sources.

Provides a general verification model for physical-layer key generation.

Abstract

Modern cryptography is essential to communication and information security for performing all kinds of security actions, such as encryption, authentication, and signature. However, the exposure possibility of keys poses a great threat to almost all modern cryptography. This article proposes a key-fusing framework, which enables a high resilience to key exposure by fusing multiple imperfect keys. The correctness of the scheme is strictly verified through a toy model that is general enough to abstract the physical-layer key generation (PLKG) mechanisms. Analysis and results demonstrate that the proposed scheme can dramatically reduce secret outage probability, so that key sources with even high exposure probability can be practically beneficial for actual secret communication. Our framework paves the way for achieving information-theoretic security by integrating various key sources, such as physical layer key generation, lattice-based cryptography, and quantum cryptography.